Social marketing: Immunizing against unethical practice

A simple approach for the catalytic conversion of primary alcohols into their corresponding esters and amides, with evolution of H2 gas using in situ formed ruthenium PNP- and PNN-pincer catalysts, is presented. The evaluation showed conversions for the esterification with turnover numbers as high as 4300, and 4400 for the amidation

Methanol-Driven Oxidative Rearrangement of Biogenic Furans - Enzyme Cascades vs. Photobiocatalysis

The oxidative ring expansion of bio-derived furfuryl alcohols to densely functionalized six-membered O-heterocycles represents an attractive strategy in the growing network of valorization routes to synthetic building blocks out of the lignocellulosic biorefinery feed. In this study, two scenarios for the biocatalytic Achmatowicz-type rearrangement using methanol as terminal sacrificial reagent have been evaluated, comparing multienzymatic cascade designs with a photo-bio-coupled activation pathway.Peer reviewe

Complementation of a phycocyanin-bilin lyase from Synechocystis sp. PCC 6803 with a nucleomorph-encoded open reading frame from the cryptophyte Guillardia theta

<p>Abstract</p> <p>Background</p> <p>Cryptophytes are highly compartmentalized organisms, expressing a secondary minimized eukaryotic genome in the nucleomorph and its surrounding remnant cytoplasm, in addition to the cell nucleus, the mitochondrion and the plastid. Because the members of the nucleomorph-encoded proteome may contribute to essential cellular pathways, elucidating nucleomorph-encoded functions is of utmost interest. Unfortunately, cryptophytes are inaccessible for genetic transformations thus far. Therefore the functions of nucleomorph-encoded proteins must be elucidated indirectly by application of methods in genetically accessible organisms.</p> <p>Results</p> <p>Orf222, one of the uncharacterized nucleomorph-specific open reading frames of the cryptophyte <it>Guillardia theta</it>, shows homology to <it>slr</it>1649 of <it>Synechocystis </it>sp. PCC 6803. Recently a further homolog from <it>Synechococcus </it>sp. PCC 7002 was characterized to encode a phycocyanin-β155-bilin lyase. Here we show by insertion mutagenesis that the <it>Synechocystis </it>sp. PCC 6803 <it>slr</it>1649-encoded protein also acts as a bilin lyase, and additionally contributes to linker attachment and/or stability of phycobilisomes. Finally, our results indicate that the phycocyanin-β155-bilin lyase of <it>Synechocystis </it>sp. PCC 6803 can be complemented <it>in vivo </it>by the nucleomorph-encoded open reading frame <it>orf</it>222.</p> <p>Conclusion</p> <p>Our data show that the loss of phycocyanin-lyase function causes pleiotropic effects in <it>Synechocystis </it>sp. PCC 6803 and indicate that after separating from a common ancestor protein, the phycoerythrin lyase from <it>Guillardia theta </it>has retained its capacity to couple a bilin group to other phycobiliproteins. This is a further, unexpected example of the universality of phycobiliprotein lyases.</p

Chemoenzymatic Hydrogen Production from Methanol through the Interplay of Metal Complexes and Biocatalysts

Microbial methylotrophic organisms can serve as great inspiration in the development of biomimetic strategies for the dehydrogenative conversion of C1 molecules under ambient conditions. In this Concept article, a concise personal perspective on the recent advancements in the field of biomimetic catalytic models for methanol and formaldehyde conversion, in the presence and absence of enzymes and co-factors, towards the formation of hydrogen under ambient conditions is given. In particular, formaldehyde dehydrogenase mimics have been introduced in stand-alone C1-interconversion networks. Recently, coupled systems with alcohol oxidase and dehydrogenase enzymes have been also developed for in situ formation and decomposition of formaldehyde and/or reduced/oxidized nicotinamide adenine dinucleotide (NADH/ NAD+). Although C1 molecules are already used in many industries for hydrogen production, these conceptual bioinspired low-temperature energy conversion processes may lead one day to more efficient energy storage systems enabling renewable and sustainable hydrogen generation for hydrogen fuel cells under ambient conditions using C1 molecules as fuels for mobile and miniaturized energy storage solutions in which harsh conditions like those in industrial plants are not applicable.Peer reviewe

Metal oxide and bimetallic nanoparticles in ionic liquids: synthesis and application in multiphase catalysis

Ionic liquids (ILs) are well established as solvents and stabilizing agents for the synthesis of metallic nanoparticles (NPs) in general. The physicochemical properties of ILs and the supramolecular organization in the liquid state are capable of directing the growth of transition metal NPs generated in situ and to subsequently protect and stabilize them. Until now, many different NPs have been successfully synthesized within these media; however, the synthesis of metal oxide and bimetallic alloy or core-shell NPs in ILs is still relatively rare. Herein, we summarize the current state-of-the-art of the synthetic methods for these materials and their application in the broad field of catalysis, including multiphase systems, hydrogenation, dehydrogenation, functionalization, as well as defunctionalization reactions